The invention relates to personal care. More particularly, the invention relates to applicators for underarm antiperspirant and/or deodorant.
A well-developed art exists regarding dispenser/applicators for personal care products. One particular area involves applicators for solid or gel antiperspirant and/or deodorant compositions. Applicators for solid and gel compositions are typically thoroughly similar to each other, with a piston (platform) upwardly movable within a cylinder (barrel) to progressively drive the composition out the barrel upper end. Due to the relative lack of stiffness of many gels and soft solids, dispensers for such compositions commonly include apertured applicator elements across the upper end of the barrel.
Certain compositions are particularly sensitive to pressure. Accordingly, the imposition of residual pressure after the initial discharge of composition may be problematic. Soft solid compositions (especially those containing silicone oils) are particularly sensitive to pressure-induced microstructural changes. PCT/US98/09656, the disclosure of which is incorporated by reference herein as if set forth at length, discloses exemplary such compositions. Thus pressure relief mechanisms have been provided. Exemplary pressure relief mechanisms are shown in U.S. Pat. Nos. 5,000,356, 5,547,302, 5,697,531, and 5,961,007, and pregrant publication US2005/0002883. One marketed dispenser resembles the cover page embodiment of the '356 patent, the disclosure of which is incorporated by reference herein as if set forth at length. That dispenser includes a one-piece molded combination elevator screw and handwheel. Superimposed reciprocal movement of the screw is caused by camming interaction of respective groups of ratchet teeth on the molded element and barrel. The downstroke of this superimposed reciprocal movement provides pressure relief. The reciprocal movement is permitted by compliance of spring unitarily formed as a portion of the element. The spring is formed of a spiral-armed flange of the handwheel. The element is formed from a material appropriate for spring operation, specifically Celcon® polyoxymethylene acetal copolymer by Celanese Corporation.